Lively winter rock pools

Not many people go rock pooling this time of year. While everyone is busy with the Christmas shopping, Junior and I have the whole beach to ourselves. This is a perfect time of year to watch the common rock pool species going about their business, to enjoy the vivid colours and, as always, make some discoveries too.

Our first surprise is a stranded flounder, possibly dropped by the heron that flapped away as we arrived on the shore.

The upturned flounder revived considerably once it was in some water.

Assuming the unmoving fish is dead, I scoop it off the muddy sand into my bucket. As I do so, it flaps a little and we stumble through the quicksand pools to find it some water. After a few minutes lying still in the bucket, it seems to revive and we release it in a deep pool alongside a good overhang. It glides straight into the shelter of the rock and buries itself in the sand.

In the dark days of winter, the colourful anemones are even more striking and this beach is a great spot for Strawberry anemones.

A strawberry anemone brightening up a pool

There are more bright red spots among the seaweeds. Dozens of juvenile Sea hares, each just a few millimetres long, are grazing away. They’re hard to spot among the red weeds, but they’re beautiful little beasts. Their red bodies look like they’re flecked with snow and their extremities are tipped in black as though they’ve been dipped upside down in black paint.

On close inspection there are many baby sea hares

Not all red glows in the Cornish rock pools are friendly. Under every overhang there seem to be twin pairs of scarlet lights glowing; the eyes of Velvet swimming crabs. These stunning creatures do not appreciate being disturbed and won’t hesitate to use their claws. Junior and I leave the ‘devil crabs’ well alone and take photos from a safe distance.

Watch your fingers! There is a Velvet swimming crab in almost every overhang.

My eye is drawn to the shimmering colours as this iridescent animal disappears into a hole in the rock.

If you ever doubted that worms could be beautiful, this might be the one to change your mind. It looks like a ragworm of some sort, perhaps Perinereis cultrifera. Attractive though these worms are, they have impressive jaws on them that I prefer not to mess with so I let it glide away.

Junior calls me over to look at strange little animals darting about in a shallow sand pool. He thinks at first they are cuttlefish from their odd-looking mouthparts. They are a type of shrimp that I haven’t seen before – and thanks to the wonders of Facebook groups, I’ve been able to confirm that they are Philocheras trispinosus (rolls off the tongue doesn’t it!).

Pilocheras trispinosus – these brilliantly camouflaged shrimps don’t sit still so taking photos was a challenge.

The calm conditions are perfect for observing the animals moving about. In the same pool we also watch a thin tellin burying itself in the sand. Although these fragile shells are common, they live hidden beneath the surface and we only usually see dead shells washed up on beaches.

Thin tellin shell before it buried itself.

Rockpooling might not be the most popular activity in December, but on a calm day, it is still as rewarding and surprising as any summer day, but without the crowds.

Happy rockpooling!

We also came across this St Piran’s hermit crab with fabulous black and white spotty eyes.Like strings of fairy lights on the kelp – Obelia geniculata hydroid.

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4 thoughts on “Lively winter rock pools”

Heather, great to see that Looe is still turning up beautiful creatures, thanks for sharing your discoveries with us hibernating rockpoolers. We look forward to exploring the delights in the spring, unless someone buys me a heated wet suit that is!

Thanks Mark. I’d recommend waders, thermals and lots of layers, but when the sun comes out on a calm day it’s not at all bad on the shore. It’s my hands that suffer in the cold water. A heated wet suit – or maybe a dry suit with a hot water bottle inside would be fab though. Either way it’s worth it – this is the best time of year for seeing stalked jellies and various other things. You should try it 🙂